For the radio does it have an auxilary in and out. i am looking to put some bass in my car and would really not like to change my head unit but i don't know if it has auxilary in and out does anyone know the answer.

if you mean an auxillary port where you can add speakers, no you don't have those.

But then again, your system already has an amplifier located in the rear. If you insist on putting in more bass, it won't be a plug-n-play installation... you'll have to figure out the speaker wires that run from your head unit onto the amplifier, then tap those wires to serve as input to your aftermarket pre-amp.

OR, if you are already satisfied with your current amp, look for the wires(post-amp) leading to the speakers and change the speakers accordingly. Make sure the speakers are compatible impedence wise otherwise, either your amp, or ur speaker will fry.

pretty sure he means an auxillary input for like Ipod or similar devices so that you can listen to them using your cars audio system. BMW sells on auxillary input for later model cars with the new generation radio. this radio can be identified by the electrical pins being flat. Earlier radios had round pins. On your 2003 car it will prbably have the earlier generation round pin radio. Some people have updated their radios in order to be able to install the aux input which is fairly cheap in price. It may be cheaper to do something aftermarket. If you have an actual IPOD then you may want to look in to the DICE.
Best Regards,

pretty sure he means an auxillary input for like Ipod or similar devices so that you can listen to them using your cars audio system. BMW sells on auxillary input for later model cars with the new generation radio. this radio can be identified by the electrical pins being flat. Earlier radios had round pins. On your 2003 car it will prbably have the earlier generation round pin radio. Some people have updated their radios in order to be able to install the aux input which is fairly cheap in price. It may be cheaper to do something aftermarket. If you have an actual IPOD then you may want to look in to the DICE.
Best Regards,

mmm... the fellow wanted "more bass"... that was my cue to make me believe he wanted a boom box of sorts ;-)